• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.429-429
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• 2012

To investigate the gettering effect of B-doped n-type monocrystalline silicon wafer, we made the p-n junction by diffusing boron into n-type monocrystalline Si substrate and then oxidized the boron doped n-type monocrystalline silicon wafer by in-situ wet and dry oxidation. After oxidation, the minority carrier lifetime was measured by using microwave photoconductance and the sheet resistance by 4-point probe, respectively. The junction depth was analyzed by Secondary Ion Mass Spectrometry (SIMS). Boron diffusion reduced the metal impurities in the bulk of silicon wafer and increased the minority carrier lifetime. In the case of wet oxidation, the sheet resistance value of ${\sim}46{\Omega}/{\Box}$ was obtained at $900^{\circ}C$, depostion time 50 min, and drive-in time 10 min. Uniformity was ~7% at $925^{\circ}C$, deposition time 30 min, and drive-in time 10 min. Finally, the minority carrier lifetime was shown to be increased from $3.3{\mu}s$ for bare wafer to $21.6{\mu}s$ for $900^{\circ}C$, deposition 40 min, and drive-in 10 min condition. In the case of dry oxidation, for the condition of 50 min deposition, 10 min drive-in, and O2 flow of 2000 SCCM, the minority carrier lifetime of 16.3us, the sheet resistance of ${\sim}48{\Omega}/{\Box}$, and uniformity of 2% were measured.

• Current Optics and Photonics
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• v.6 no.3
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• pp.236-243
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• 2022

Monocrystalline silicon has excellent properties, but it is difficult to design and manufacture silicon-based mirrors that can meet engineering applications because of its hard and brittle properties. This paper used monocrystalline silicon as the main mirror material in an imaging system to carry out a feasibility study. The lightweight design of the mirror is completed by the method of center support and edge cutting. The support structure of the mirror was designed to meet the conditions of wide temperature applications. Isight software was used to optimize the feasibility sample, and the optimized results are that the root mean square error of the mirror surface is 3.6 nm, the rigid body displacement of the mirror is 2.1 ㎛, and the angular displacement is 2.5" under the conditions of a temperature of ∆20 ℃ and a gravity load of 1 g. The optimized result show that the silicon-based mirror developed in this paper can meet the requirements of engineering applications. This research on silicon-based mirrors can provide guidance for the application of other silicon-based mirrors.

• Current Photovoltaic Research
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• v.5 no.4
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• pp.105-108
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• 2017

The reactive ion etching (RIE) technology which enables nano-texturatization of surface is applied on monocrystalline silicon solar cell. The additional RIE process on alkalized textured surface further improves the blue response and short circuit current. Such parameter is characterized by surface reflectance and quantum efficiency measurement. By varying the RIE process time and matching the subsequent processes, the absolute efficiency gain of 0.13% is achieved. However, the result indicates potential efficiency gain could be higher due to process integration. The critical etch process time is discussed which minimizes both front surface reflectance and etching damage, considering the challenges of required system throughput in industry.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4689-4695
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• 2011

Nanodiamond is a relatively new nanomaterial with broad prospects for application. In this paper, a variety of methods were used to analyze comprehensively chemicophysics properties of the detonation monocrystalline and synthetic polycrystalline nanodiamond, XRD spectroscopy, EDS, HRTEM, FTIR, Raman spectroscopy, TGA-DTA and BET. The results show that the monocryctalline detonation nanodiamond particles are spherical or elliptical shape of 4nm ~ 6nm grain size and the polycryctalline synthetic nanodiamond particles are angular shape of 80nm ~ 120nm grain size. The surface of the monocrystalline and polycrystalline nanodiamond contain hydroxy, carbonyl, carboxyl, ether-based resin, and other functional groups. The phase transition temperature of the monocrystalline detonation nanodiamond in the $N_2$ is about $650^{\circ}C$.

• Journal of the Korean Solar Energy Society
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• v.32 no.2
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• pp.113-119
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• 2012

This study aims to examine the effect of the combined application of green roof and PV system on the PV efficiency by measuring the temperature and performance of PV module in order to reduce the temperature on the roof using roof planting system and determine the potential of efficient increase in solar-light power generation. In the experimental methodology, either monocrystalline or polycrystalline PV module was installed in green roof or non-green roof, and then the surface temperature of PV was measured by TR-71U thermometer and again the performance, module body temperature, and conversion efficiency were measured by MP-160, TC selector MI-540, and PV selector MI-520, respectively. As a result, the average body temperature of monocrystalline module was lower by $6.5^{\circ}C$ in green roof than in non-green roof; that of polycrystalline module was lower by $8.8^{\circ}C$ in green roof than in non-green roof. In the difference of generation, the electricity generation of monocrystalline module in green roof was 46.13W, but that of polycrystalline module was 68.82 W, which indicated that the latter produced 22.69W more than the former.

• Proceedings of the Korean Ceranic Society Conference
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• 1986.12a
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• pp.287-304
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• 1986

High quality monocrystalline $\beta$-SiC thin films were grown via two-step process of conversion of the Si(100) surface by reaction with $C_2H_4$ and the subsequent chemical vapor deposition (CVD) at $1360^{\circ}C$ and 1 atm total pressure. Four dopants, B and Al and p-type, and N and P for n-type, were also incorporated into monocrystalline $\beta$-SiC thin films during the CVD growth process. IR and Raman spectroscopies were used to evaluate the quality of the undoped $\beta$-SiC thin films and to investigate the effects of dopants on the structure of the doped $\beta$-SiC thin films. The changes in the shape of IR and Raman spectra of the doped thin films due to dopants were observed. But the XTEM micrographs except for the B-doped and annealed films showed the same density and distribution of stacking faults and dislocations as was seen in the undoped samples, The IR and Raman spectra of the B-doped and annealed films showed the broad and weak bands and one extra peak at the 850 $cm^{-1}$ respectively. The SAD pattern and XTEM micrograph of the B-doped and annealed film provided the evidence for twinning.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.249-249
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• 2010

We investigated novel surface treatment and its impact on silicon photovoltaic cells. Using 2-step etching methods, we have changed the nanostructure on pyramid surface so that less light is reflected. This work proposes an improved texturing technique of mono crystalline silicon surface for solar cells with sub-nanotexturing process. The nanotextured silicon surface exhibits a lower average reflectivity (~4%) in the wavelength range of 300-1100nm without antireflection coating layer. It is worth mentioning that the surface of pyramids may also affect the surface reflectance and carrier lifetime. In one word, we believe nanotextruing is a promising guide for texturization of monocrystalline silicon surface.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.8
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• pp.654-658
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• 2011

This paper was investigated the electrical properties for optimal operating conditions of monocrystalline silicon solar cell. The output of electricity for monocrystalline solar cell was investigated according to the distances between solar cell and halogen lamp and to the resistances by the variable resistor.

• Advances in Energy Research
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• v.7 no.2
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• pp.123-134
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• 2020

Photovoltaic systems are progressively attached importance and their installed capacity increases day by day because of their reliability, decremented installation and operating cost and simple construction structure. Generated power obtained from a photovoltaic system changes depending upon regional distinctness, and It can be estimated approximately by taking into consideration mean global radiation amount, temperature and humidity. However, there may be different regional negative or positive factors like dust, air pollution, desert powder which affect generated power. The best reliable data for a region can be obtained from the existing photovoltaic system in the region. For this purpose, a monitoring system for 1000W monocrystalline photovoltaic system constructed at Kocaeli University Uzunciftlik Nuh Cimento Vocational High Scholl is prepared. The installed monitoring system shows and records real values generated from the photovoltaic system and environmental data. In the study, Instantaneous data obtained from the monitoring system for October 2018 and 7th October 2018 is given within figures. Additionally, daily and monthly total energy productions of the photovoltaic system are given for October 2018 and date interval between July 2018 and March 2018, respectively.

• Smart Structures and Systems
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• v.22 no.5
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• pp.495-508
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• 2018

Shape memory alloys (SMAs) exhibit superelasticity given the ambient temperature is above the austenite finish temperature threshold, the magnitude of which significantly depends on the metal ingredients though. For the monocrystalline CuAlBe SMAs, their superelasticity was found being maintained even when the ambient temperature is down to $-40^{\circ}C$. Thus this makes such SMAs particularly favorable for outdoor seismic applications, such as the framed structures located in cold regions with substantial temperature oscillation. Due to the thermo-mechanical coupling mechanism, the hysteretic properties of SMAs vary with temperature change, primarily including altered material strength and different damping. Thus, this study adopted the monocrystalline CuAlBe SMAs as the kernel component of the SMA braces. To quantify the seismic response characteristics at various temperatures, a wide temperature range from -40 to $40^{\circ}C$ are considered. The middle temperature, $0^{\circ}C$, is artificially selected to be the reference temperature in the performance comparisons, as well the corresponding material properties are used in the seismic design procedure. Both single-degree-of-freedom systems and a six-story braced frame were numerically analyzed by subjecting them to a suite of earthquake ground motions corresponding to the design basis hazard level. To the frame structures, the analytical results show that temperature variation generates minor influence on deformation and energy demands, whereas low temperatures help to reduce acceleration demands. Further, attributed to the excellent superelasticity of the monocrystalline CuAlBe SMAs, the frames successfully maintain recentering capability without leaving residual deformation upon considered earthquakes, even when the temperature is down to $-40^{\circ}C$.